Point-Of-Care Testing (POCT) and in-situ solutions to medical diagnosis and biochemical detections are used for early and rapid identification of target specimens.
Biophotonic sensors integrated with complementary Micro-ElectroMechanical Systems (MEMS) integrate optics with biological testing/manipulation for efficient and rapid bio-sensing, thus realizing the concept of Lab-on-a-Chip (LOC) or Micro-Total Analysis Systems (μTAS). However, for the sake of convenience and the ability to handle smaller sample volumes of chemical and biological species, there are some issues associated with conventional biophotonic based bio-sensing systems, such as miniaturization and portability, that have hindered their integration in LOC and μTAS applications.
Silicon waveguide-based biophotonic sensors have been previously contemplated due to the fact that silicon waveguides can be miniaturized to the order of microns to a few nanometers in order to achieve single mode conditions for wave propagation. The potential commercial advantages of using silicon based platforms are cost effectiveness and ease of microfabrication. However, silicon based platforms typically have two potential drawbacks that can affect biosensor systems, namely, problems with miniaturization and secondly, the typically high material absorption properties of silicon in the optical spectra that are generally used for biosensing, such as the visible and infrared spectra.